The present invention relates to a moving picture high-speed coder and a moving picture high-speed coding method, and more particularly, to high-speed processing by a picture compression unit that executes an inter-frame predictive coding.
In the picture compression unit that executes an inter-frame predictive coding, there is the method of finding a difference between a part and the part having highest correlation therewith to lessen data volume to be coded as effective means in order to improve picture quality.
Wider is a range of vector retrieval, more precise retrieval can be carried out, but the processing volume increases drastically. In general, in case that a high-speed compressing process is required, the method is employed of decreasing the operational volume by narrowing this retrieval range and by aborting the retrieval when the part having relatively high correlation was found. This method was disclosed in JP-A-271514/1998.
However, in these methods, the problem exists: In case that the part having high correlation can not be found in the retrieval range like a scene with violent motion, not only a compression speed becomes late because the operational volume increases the most, but also it finally becomes more efficient in coding that an intra-frame compression is carried out.
Also, in JP-A-155149/1998 is described the technique of coding by altering a frame rate in a terminal according to processing capacity, but the problem exists that a smooth regenerative picture became impossible to obtain when the frame rate is altered.